Traffic controlling system for railroads



Dec. 4, 1934. o, s FIELD TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Filed June 15, 1932 58. IN 55 m s m w nub! 69. on .92am Le a uudwcou no not. verso-3m wo avun 05.2

ATTORNIEY Patented Dec. 4, 1934 UNITED STATES PATENT OFFICE RAILROAD Oscar S. Field, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

Application June 15, 1932, Serial No. 617,264

14 Claims.

This invention relates to timing apparatus more particularly adaptable for use in traffic controlling systems for railroads.

It is often unsafe to operate a track switch,

or a crossover or to clear a signal immediately, without first operating another traffic controlling device and waiting a period of time to allow the operation of such other device to have taken place. For instance, it is unsafe to operate a track switch immediately after placing the signal at stop, for there may be a fast approaching train which cannot stop in response to such signal indication before it reaches the track switch. Under certain conditions, it is not sufficient to have timing apparatus for measuring one particular time period only, but it is desirable not to close a particular contact until different periods of time have elapsed depending on local conditions. In accordance with the present invention, it is proposed to provide a circuit arrangement and associated devices whereby numerous periods of time may be measured by the same apparatus. It is also proposed to use apparatus with few mechanical parts. Other objects, purposes and characteristic features of the present invention will in part be obvious from the accompanying drawing and will in part be more specifically described hereinafter.

In describing the invention in detail, reference will be made to the accompanying drawing which shows conventionally one specific embodiment of the present invention.

Referring to the drawing, the relay M may be a signal-at-stop relay, which is only energized when the various signals associated with a track switch are at stop, or this relay M may be controlled in any other way depending upon the manner in which the invention is to be applied, it being for the present assumed that the invention is to be used to delay the operation of a track switch after placing a. signal to govern traflic thereover at stop. The switch S may be manually or electrically operated, and is employed to change the timing characteristic of the device, and if opened affords a certain checking function desirable in certain systems. The relays TR and TR are thermal relays of the type which are compensated against changes in surrounding room temperatures, as well known to those skilled in this art. The adjustable resistances R and R are used to vary the closing periods of thermal relays TR and TR the adjustment of these resistances having practically no effect on the opening periods of these relays.

The stick relays SR and SR. perform the usual hold-over function characteristic of relays of this kind.

- Operation Let usfirst assume that the switch S is open, and let us observe how the closure of contact 1 of the relay M will result in connecting the terminal of a suitable battery to the various terminating wires after the lapse of various intervals of time. Closure of the contact 1 of the relay M will first result in energization of the heating coil 2 of the relay TR by closure of the following circuit: beginning at the terminal of said battery, front contact 1 of the relay M, wires 3 and 4, adjustable resistance R heating coil 2, wire 5, back contact 6 of the stick relay SR and to the otherterminal of said battery. The closure of this circuit results in heating of the coil 2, thereby causing the thermal relay to be gradually moved to its heated dotted position, in which position the following pick-up circuit for the relay SR is closed:-- beginning at the terminal front contact 1 of relay M, wires 3 and 4, front contact 10 of the thermal relay TR wires 11 and 12, winding of the relay SR to the other terminal With the relay SR picked up, it will be stuck up through the following stick circuit:beginning at the terminal front contact 1 of the relay M, wires 3 and 4, resistance R heating coil 2, wire 5, stick contact 6 of the relay SR wires 13 and 12, winding of the relay SR to the other terminal It will be noted that the circuit just traced includes the heating coil 2 in series with the winding of the stick relay SR Since the resistance of the relay SIR. is fairly high, the current will be reduced to a very low value, so that the thermal relay TR will be permitted to cool and eventually again close its back contact 10.

When this occurs, the following energizing circuit for the heating coil 22 of the thermal relay TR is closed:- beginning at the terminal front contact 1 of the relay M, wires 3 and 4, back contact 10 of the stick relay TR wires 14 and 15, front contact 16 of the relay SR wires 17 and 18, adjustable resistance R heating coil 22 of the relay TR wire 23, back contact 24 of the relay SR to the other terminal of said battery.

After another interval of time, the thermal relay 'IR. will be heated to a temperature to close its front contact resulting in the closure of a pick-up circuit for the relay SR beginning at the terminal (-1-) of said battery, front contact 1 of the relay M, wires 3 and 4, back contact 10 of the thermal relay TR Wires 14 and 15, front contact 16 of the relay SR wires 1'7 and 18, front contact 25 of the relay TR wires 27 and 28, Winding of the relay SR to the other terminal The relay SR will of course be picked up thereby closing the following stick circuit: beginning at ,theterminal front contact 1 the relay M,'wires 3 and 4, back contact 10, wires 14 and 15, front contact 16 of the relay SR wires 17 and 18, resistance unit R heating coil 22, wire 23, stick contact 24 of the relay SR wires 29 and 28,

winding of the relay SE to; the other terminal wires 32 and 33, back contact 26 of the thermal relay TR to the wire 30.

If we now assume that fifteen seconds are required to heat the coils of the thermal relays TR and TR to a temperature to close their energizing current for the stick relay SR flowing through its heating coil, and that it requires two and one-half minutes for the thermal relay TR to cool to a temperature to reclose its back contact and with energizing circuit for the stick relay SR flowing through its heating coil, various periods of time will elapse between the closure of the contact 1 of the coilM and the instant that the terminal of the battery is connected to the wires 30, 40 or 50, respectively; It is readily apparent that the terminal is connected to the wire '50 after the lapse of two periods of time, namely, the time necessary to heat the thermal relay TR and the time required for this relay TR to cool, so that the total period of time following the closure of contact 1 is fifteen seconds plus one and one-half minutes or a total of one and three-fourth minutes before the terminal is connected to the wire 50. It is readily apparent that the contact 31 of relay SR closes fifteen seconds later, namely, the time required for the thermal relayTR to be heated, so that the terminal is connected to the wire 40 fifteen seconds later, or after the lapse of two minutes following the closure of tics of the thermal relays TR and TR as arbitrarily selected above, time periods of one and three-fourth minutes, two minutes and four and one-half minutes may be measured with the contact S open. If now the contact S is closed, no cooling of the thermal relay TR will be required to pass the current from the terminal through the front contacts 1 and 16 of the relays M and SR so that the time periods heretofore mentioned will be reduced by one and one-half minutes, thus resulting in time period lapses of three minutes, one-half minute and one-fourth minute with the switch S closed. It

is, of course, understood that the relays used may have any'suitable timing characteristics.

Having thus shown and described one specific embodiment of the invention, it is desired to be understood that the particular embodiment Fof the invention illustrated has not been selected for the purpose of showing the scope of the invention nor its precise construction, and that various changes and modifications may be made to adapt the invention to the particular problem encountered in practicing the same-all without departing from the spirit or scope thereof, except as demanded by the scope of the following claims.

What I claim as new is:

1. In combination in a railway signal system, a thermal relay, a stick relay, an energizing circuit for said thermal relay including a back contact of said stick relay, a pick-up circuit for said stick relay including a front contact of said thermal relay, a control circuit including a front contact of said stick relay and a back contact of said thermal relay, and a separate contact for at times shunting said back contact of said thermal relay, whereby said control circuit may be closed upon heating and cooling of said ther- I ion a thermal relay, a stick relay, an energizing circuit for said thermal relay including a back contact of said stick relay, a pick-up circuit for said stick relay including a front contact of said thermal relay, a control circuit including a front contact of saidstick relay and a back contact of said thermal relay, and manually operable means for at times shunting said back contact of said thermal relay in said control circuit.

3. Incombination, two thermal relays, a stick relay for each thermal relay, a pick-up circuit for each stick relay closed upon heating of its associated thermal relay, an energizing circuit for each thermal relay including a back contact of its associated stick relay, and a control circuit dependent upon front contacts of said stick relays and back contacts of said thermalrelays.

4. In combination, two thermal relays, a stick relay for each thermal relay, a pick-up circuit for each stick relay closed upon heating of its associated thermal relay, an energizing circuit for each, thermal relay including aback contact of its associated stick relay, a front contact of one of said stick relays included in the energizing circuit of the other of said thermal relays, and a control circuit including a front contact of the stick relay associated with said other thermal relay.

5. In combination, two thermal relays, a stick relayfor each thermal relay, a pick-up circuit for each stick relay closed upon heating of its associated thermal relay, an energizing circuit" for each thermal relay including a back contact of its associated stick relay, a front contact of one of said stick relays included in the energizing circuit of the other of said thermal relays, and a control circuit including a front contact of the stick relay associated with said other thermal relay and also including a back contact of said other thermal relay.

6. In combination, a first thermal relay, a first stick relay having a back contact included in the energizing circuit of said first thermal relay and having a pick-up circuit including a front contact of said first thermal relay, a second stick relay, a second thermal relay having an energizing circuit including a back contact of said second stick relay and a front contact of said first stick relay, and a control circuit including a ,front contact of said second stick relay.

7. In combination, a first thermal relay, a first stick relay having a back contact included in the energizing circuit of said first thermal relay and having a pick-up circuit including a front contact of said first thermal relay, a second stick relay, a second thermal relay having an energizing circuit including a back contact of said second stick relay a front contact of said first stick relay and back contact of said first thermal relay, and a control circuit including a front contact of said second stick relay.

8. In combination, a first thermal relay, a first stick relay having a back contact included in the energizing circuit of said first thermal relay and having a pick-up circuit including a front contact of said first thermal relay, a second stick relay, a second thermal relay having an energizing circuit including a back contact of said second stick relay and a front contact of said first stick relay, and a control circuit including a front contact of said second stick relay and a back contact of said second thermal relay.

9. In combination, a first thermal relay, a first stick relay having a back contact included in the energizing circuit of said first thermal relay and having a pick-up circuit including a front contact of said first thermal relay, a second stick relay, a second thermal relay having an energizing circuit including a back contact of said second stick relay a front contact of said first stick relay and back contact of said first thermal relay, and a control circuit including a front contact of said second stick relay and a back contact of said second thermal relay.

10. In combination, a first thermal relay, a first stick relay having a back contact included in the energizing circuit of said first thermal relay and having a pick-up circuit including a front contact of said first thermal relay, a second stick relay, a second thermal relay having an energizing circuit including a back contact of said second stick relay a front contact of said first stick relay and back contact of said first thermal relay, a control circuit including a front contact of said second stick relay.

11. In combination, a first thermal relay, a first stick relay having a back contact included in the energizing circuit of said first thermal relay and having a pick-up circuit including a front contact of said first thermal relay, 8. second stick relay, a second thermal relay having an energizing circuit including a back contact of said second stick relay a front contact of said first stick relay and back contact of said first thermal relay, a control circuit including a front contact of said second stick relay and a back contact of said second thermal relay, and a time selecting contact for shunting said back contact of said first thermal relay.

12. In combination, a plurality of circuits to be controlled, a control contact, a plurality of thermal devices, governing means for causing each of said devices to be heated and cooled in sequence upon the closure of said control contact, and means including said devices and said governing means for rendering said circuits successively responsive to control by said control contact.

13. In combination; a plurality of circuits to be controlled; a control contact; a plurality of thermal relays, one for each of said circuits; governing means for causing said thermal relays to be respectively heated and cooled in sequence upon the closure of said control contact; and means for closing that particular one of said circuits associated with a particular thermal relay upon the completion of its heating and cooling operation, whereby said circuits are closed sequentially and predetermined times respectively after the closure of said control contact.

14. In combination; a plurality of circuits to be controlled; a control contact; a plurality of thermal relays, one for each of said circuits; governing means for causing said thermal relays to be respectively heated and cooled in sequence upon the closure of said control contact; means for closing that particular one of said circuits associated with a particular thermal relay upon the completion of its heating and cooling operation; and other means for at times governing said first mentioned means so that the cooling time of the first of said plurality of thermal relays is ineffective; whereby said circuits are closed sequentially with certain predetermined times respectively after the closure of said control contact if said other means is ineffective, but are closed sequentially and certain other shorter predetermined times respectively after the closure of said control contact if said other means is effective.

OSCAR S. FIELD. 

